There is a constant trend to try to decrease the thickness of electronic scales. In the prior art, the electronic scales are provided with four feet bearing on the floor, tiles, carpet, etc. Each foot houses a load cell. One example of such configuration is given by document U.S. Pat. No. 4,800,973.
There is also a constant trend to try to decrease the cost of such electronic scales.
One problem arises when the overall thickness of the scale is decreased, because the height of the feet (i.e. clearance) is not large enough in case the scale is lying on a rather deep carpet, like in a bedroom fitted carpet, or on an uneven floor. If the underbody of the scale touches the floor, this results in an inaccurate, even substantially wrong, weight measurement.
Therefore, some attempts have been done to provide a so-called “sandwich structure” with a rigid top plate, a rigid bottom plate and load cells interposed therebetween. The structure taught by US20100133016 exhibits shortcomings because the top plate may rub against the bottom plate which causes inaccurate weight measurement. Mechanical guidance is quite tricky to make proper use of load cells.
Therefore it remains a need to propose a weighing scale which exhibits a thickness of less than 20 mm, and which exhibits a simplified mechanical configuration.